Australia's first anti-slavery commissioner has told a Melbourne conference disengaged temporary migrant workers were emerging as a key issue for the farm sector.
NSW Anti-Slavery Commissioner Steve Cockayne was speaking to the annual Fair Farms conference on the work done by his team, during the last 12 months.
He said authorities estimated 41,000 people were living in conditions which could best be described as slavery.
"We still do have people, in this country, who treat other people as if they owned them, by forcing them to work, keeping them in debt bondage, engaging in deceptive recruiting and even keeping people in servitude," Mr Cockayne said
"Some of these people are living and working in farming communities, certainly in NSW where I am based.
"There are a small number of temporary migrant workers who have come under the Pacific Australia Labour Mobility scheme have wound up in situations that clearly meet the national and international test of forced labour, or debt bondage."
He stressed it was only a very small minority.
"For most the experience is a positive and deeply rewarding one," he said.
But modern slavery put both businesses and workers in harms way and threatened Australia's reputation in the region, when it came to such schemes as PALM.
"Instead of being a partnership for prosperity, such schemes become the sower of seeds of trauma and tragedy," he said.
He said he had documented evidence of "threats and intimidation" from "dodgy labour hire contractors" to discourage workers from speaking up about work conditions and on farm accidents.
"People are being forced to live in substandard accommodation, passports are withheld and wages improperly docked and being defrauded, quite frankly, in amounts they were being charged for access to the kitchen and laundry.
"In fairness, this is the experience, I believe of a minority of temporary migrant workers employed on farms, and under the PALM scheme - for most the experience is a positive and deeply rewarding one."
Mr Cockayne said the horticulture sector also needed to seriously consider the "high" disengagement rates from authorised employers by temporary migrant workers who had left their jobs or felt unable to raise issues at their workplace.
"Disengagement is a foreseeable and predictable part of any mass migrant worker scheme," he said.
"The issues are about recruitment, about accommodation, about how they are paid, about how they are charged, or overcharged.
"Recruitment is too often deceptive and often involves incurring debts to recruiters and powerful figures, in their home communities - that places temporary migrant workers and their families at risk when things go wrong in Australia, as they will."
In the Riverina, NSW, recently, he said he had heard from law enforcement agencies some disengaged temporary migrant farm workers were "turning to shop lifting and petty crime to get food and clothes."
He said disengagement was a systematic problem, yet authorities were not viewing it that way.
"The current arrangements we have in place miss this bigger picture," he said.
"We have local councils, environmental and planning authorities looking at fitness for accommodation, we have Safework and workplace regulators working at safety, immigration authorities looking at visa status and foreign affairs looking at offshore recruitment.
"The failure to join the dots and see the bigger picture here contributes to the climate of dependence, coercion and silencing that can emerge for a small minority of workers."
Mr Cockayne said the answer was not more regulation, but using it the available data better.
"If we move to a single national labour hire licencing scheme, as is now under active consideration by the federal government, any regulator given responsibility must have the powers to allow them to join up these dots and see the bigger picture.
"It's only through collective action that we address system failure, like this - each actor along the value chain has a key role to play and government has a responsibility to put in place clear regulations, effective oversight and enforcement arrangements to ensure the system is producing the social outcomes we all want to see."
But he said he still heard "denial and blame shifting
"I still hear complaints that compliance costs are too high, and I see regulators sticking narrowly to their particular purview, without understanding the bigger picture of the culture of intimidation, debt bondage and possibly sexual servitude that is emerging in a few dangerous pockets," he said.
When workers disengaged, it meant service providers in healthcare, housing and police were not able to predict demand, he said.
But it was not in the sector's interests to have a workforce that risked "destitution, social stigmatisation and criminal activities.
"It's not in the sector's interest to be unprepared for legislation - Europe is moving towards an import plan on goods subject to forced labour, " he said.
"This will mean, down the value chain, come expectations that you will get on top of these problems in a way that allows you to keep accessing the single market for your exports and being able to work with European investors."